Sewage ejector



AUg- 26, 1930- l H. E. LA BouR 1,774,234

EEEEEEEEEEE OR Aug. 26, 1930.

H4 E. LA BOUR SEWAGE EJECTOR Filed Jan. 20, 1927 2 sheets-shea 2 Patented Aug. 26, 1930 HARRY E. BOUB, OF HOHEWOOD, ILLINOIS SEWAGE EJECTOB vApplication ined January 20, 1927. Serial No. 162,295.

, This invention relates to means for handling sewage, and the like, such as 1s required for raising sewage from a lower level to a higher level. 5 Sewage ejectors of the pneumatic type are in common use. They require compressed air which is often dilicult and expensive to provide. The operation is expensive because of the loss of energy in the compressed air. The pneumatic ejector depends for its successful operation upon keeping the inlet check valve tight. In case this valve does not close the pressure exerted by the compressed air discharges the accumulated sewage back into the line and failure of the system results.

Because of the simplicity of the centrifugalpump, various attempts have been made to utilize the same directly for this work and, in fact, there are a number of pumps on the market, but a centrifugal pump which is designed for anything like efficient operation cannot be built to take care of solid matter except in a fnel divided form. For this reason the centri ugal pump has been only partially successful.

Heretofore the pump has been disposed in a pit at or below the sump with the result that it is in an undesirable position, particularly for direct drive by a motor.

In the preferred embodiment of the present invention, I provide a sump and between the incoming sewer and the sump I provide a strainer to intercept such solids as cannot be eiiicient-ly handled by the pump. As a novel feature of my invention I employ a self priming pump operated directly by a motor, this pump being preferably of the type disclosed 1n my prior Patent No. 1,578,236, which pump is disposed in a convenient position above the sump. This pump takes the eluent from the sum and discharges the same back through t e strainer to drive the solid material thereupon into the discharge to the sewer main. I provide a lateral outlet from the incoming sewer pipe or service pipe to relieve any leakage of the inlet check valve when the pump is 1n operation, so that in no case can the pump discharge the sewage back into the service mains.

I interpose a screen in this lateral outlet so that solid matter will not be discharged into the sump, but will be retained in the inlet connection until such time as the inlet check valve is again opened. The strainer is disposed in a'tank which is in turn disposed within the sump, said sump being preferably a concrete basin. Obviously, this may be varied within my invention. As a further feature of my invention I provide means for positively closing the outlet of the eluent dischar e from the strainer so that the full force o the pump may be exerted upon the discharge of the eliluent and dislodgment of the solid matter from the strainer. It is an o5 important feature of this invention that the Isame can be applied to pits or sum s now in existence. The ,pump and motor eing disposed above th'e pit permit of a mode of operation and a capacity which other methods of operation do not permit.

While I explain the invention with reference to the handlin of sewage and with reference to the detalls of a specific embodiment, it is to be understood that the invention is not to be limited to the particular use nor to the details of construction.

In order to acquaint those skilled in the art with the manner of constructing and operating a device embodying my invention,

I shall now describe in connection with the accompanying drawings a specific embodiment of the same.

In the drawings Figure 1 is a vertical section through the 85 sump showing the strainer box and pump in elevation, part of the strainer box being broken away to show the valve construction;

Figure 2 is a vertical section taken at right angles to the view of Figure l through the strainer box and connections thereto; and

Figure 3 is a fragmentary elevational view showing a modified form of outlet valve.

A suitable sump is provided preferably in the form of a concrete pit l, and this pit is provided with a cover member 2. Within the pit there is disposed the strainer box 3. Obviously the strainer box may be disposed in a separate pit from the one forming the sump, but it is a desirable feature of the invention to have the strainer box 3 disposed within the sump. This strainer box 3 is supported on a suitable bracket 4 mounted on the side wall of the pit 1. The strainer box contains a strainer plate 5 which may be of perforated sheet metal, or the like, and in the present instance is a fiat plate disposed diagonally Within the confines of the box 3,which box may be rectangular or circular in form, or any desired form. The strainer box 3 may be made of a casting having suitable inlet and outlet connections as will be explained later. A cover member 6 is secured to the to) of the box 3, being fastened by suitable anges or the like. The strainer 5 divides the box 3 into two compartments 7 and 8, the com artment 7 being on the incoming side o the sewage and being' arranged to intercept solid matter such as cannot conveniently be handled by a centrifugal pump. The incoming service main 9 opens into the chamber or compartment 7 and it has a check valve 10 which, in the present instance, is located just inside the compartment 7, although obviously this might be located in the main 9 if desired.

I provide an overflow connection which in the present instance consists of an open standpipe 11 extending up to substantially the top of the sump, and in this open connection I provide a screen or strainer 12. The check valve should be located between said overfiow connection 11 and the chamber 7, so that as will be described later, when the pressure of the pump is applied to discharging the solid and liquid matter from said chamber 7, the checkvalve 10 will close and prevent the discharge of sewage from the chamber 7 back into the service main 9.

Preferably a slight enlargement or chamber 13 is formed below the strainer 12 so that solid matter may be retained therein during the time that the check valve is closed or partly closed.

A sewage discharge connection comprising a pipe 14 is connected to the interior of the chamber 7 preferably at the lower end of the screen or strainer 5. A non-return valve 15 is preferably interposed in said discharge line 14. This discharge line 14 runs to the sewer main for the discharge of the sewage from this part of the system.

The chamber or compartment 8 has two connections; one, an outlet connection 17 for the outlet of eiiluent, that is, the liquid which remains after the solid matter has been intercepted, and the effluent flows through the connection 17 into the sump providing a body of liquid 18 which may be satisfactorily handled by the pump 19.

This connection 17 is preferably placed adjacent the top of the box 3 for the purpose of retaining the box substantially full of liquid, so that any solid m' tter remaining on the screen will be wet with liquid, first to prevent it from drying uponthe screen or strainer and, second, so that its weight is borne in part by the liquid according to the law of Archimedes.

The pump I9 has a suction pipe 20 leading to the lower part of the sump and it has a disn charge connection comprising a pipe 21 leading into the chamber 8 preferably near the bottom ofthe'same.

Since, as will be apparent from the description of operation later, it is necessary to close the outlet 17 when the pump 19 is 4discharging liquid from the sump into the chamber 8, 1 provide a valve which is closed when the pump 19 operates. 'The valve may be provided to close in a number of different ways. I have shown the preferred manner which consists in causing the liquid flow of discharge from the pump 19 creating a positive force for closing the valve 22. This valve 22 is a lift valve closing the opening of the discharge connection 17 and seating with internal pressure in the chamber 8. i

The valve is mounted on a swinging lever 23 pivoted at 24 within the chamber 8.

The lever 23 has a continuation 25 upon which is mounted a vane or piston 26 fitting loosely in a cylinder or pocket 27 connected to the discharge pipe 21.

The pump 19 is preferably of the type disclosed in my patent above mentioned and it comprises a pump casing 28 in which there is mounted a suitable runner, the shaft 29 of which is directly connected to an electric motor 30 for driving the same. The pump has a separating chamber 31 in which gas and liquid are separated, the air being discharged out of the discharge pipe 21 and the liquid being in part during the priming operation returned to the pump casing and into the runner to perform the priming operation, as is described in the aforesaid patent.

The motor 30 is controlled by the float controlled switch 32, a suitable operating fioat 33 being disposed Within the sump and subject to the level of the liquid 18. Provision is made for starting the pump when a predetermined high level is attained and for stopping the pump when a predetermined low level 1s attained, as is Well understood by those skilled 'in the art.

I provide a iiushing connection 34 which comprises a pipe leading to a source of Water under pressure and having branches 35 and 36 leading to suitable flushing nozzles 37 and 38, respectively. A suitable control valve 39 is provided. Separate valves may be provided in the branches 35 and 36, if desired. The purpose of these flushing nozzles is to provide means for periodic cleaning of the screens or strainers 5 and 12, respectively.

In Figure 3 I have shown a modified form of valve for closing the outlet 17, this valve comprising a hinged iiap valve 40 adapted to be held' normally by gravity in a vertical position. An extension 41 of the discharge pipe 2l is placedlin such position that the liquid discharged by the pump strikes the valve and swings it against the seat 42 which is arranged at an angle to the vertical, so that it normally is open when no liquid is {iowmg out of the discharge pipe 41, but so that the discharge of liquid from the pipe 41 will press the Valve 40 to its seat 42 and close oii:l the connection 17.

The operation of the system is as follows.

Liquid enters the compartment 7 through the incoming service main 9, the valve 10 being automatically swung open and permitting the raw Sewage to be discharged into the compartment 7. Solid matter is intercepted by the screen or strainer 5 and the eiiiuent or liquid portion passes into the compartment 8, filling the same to the level of the discharge connect-ion 17 and then owing out the .discharge connection 17 into the sump formed in the basin 1.

The solid matter such as cannot be handled by the pump 19 is retained in the chamber 7, and the proportions of the system are so de-v termined that the level of the liquid 18 will rise and start the pump before an excessive accumulation of solid matter in the chamber 7 occurs.

At this time the valve 22 is opened, being swung open by gravity.

The piston or disc 26 does not necessarily close ofi' the discharge connection of the pump 19 as there is no necessity for so doing, the pipe 21 extending above the top of the sump and above the top of the box 3.

When the liquid 18 has risen to the point where the switch 32 is closed, to energize the circuit of the motor the pump is started and it quickly picks up its own suction, raising liquid from the sump and discharging the same through the discharge connection 21. The` discharge of liquid pushes the piston or disc 26 outwardly, in a clockwise direction as viewed in Figure 1, swinging the armsy 25 and 23 about the pivot 24 and closing the valve 22.

Thereupon pressure builds up in the compartment 8 and liquid with the contained solid matter isthen driven out through the discharge connection 14 past the check valve 15.

The check valve 10.in the incoming line 9 is automatically closed. In the event 4thatthis valve should leak or should be blocked partly open, the leakage therefrom merely backs up in the service main 9 to the point ofv the level of the stand-pipe 11, the liquid thereupon overiiowing into the sump inlthe pit 1 doing no further harm than lowering to some extent the efficiency of the pump. It is to be observed that of the incoming raw sewage, or of the sewage discharged from the compartment or chamber 7, solid Vmatter is prevented from. entering the sump by the intercepting screen or strainer 12.

Likewise, during the operation of discharge by the pump any raw sewage tending to accumulate will depositits solid matter in the chamber' 13 and the liquid eiiluent will overflow the stand-pipe 11 and be discharged into the sump. v

rObviously the service main 9 may enter the chamber 7 at any convenient point, that is, it is not restricted to entering the chamber 7 at the upper portion thereof.

An attendant periodically inspects the plant and flushes the screens or strainers 5 and 12 with Water under pressure through the nozzles 38 and 37, respectively.

Upon lowering of the level in the sump to a predetermined minimum, the switch 32 opens the motor circuit and the pump stops. Thereupon the liquid in the chamber 8 tends to siphon back through the pipes 21, pump 19, pipe 20, into the sump and this action, together with gravity acting on the levers 23 and 25, positively opens valve 22.

At the same time the siphoning action puts a suction on the inner end of the connection 17 tending to open the valve 22.

The .valve arrangement shown in Figure 3 may be employed. It need not be placed in the lower part of the compartment 8. If desired, an additional weighted arm may be connected to the valve 40 to assist its opening operation.

I do not intend to be limited to the details shown and described.

I claim 1, In combination, a strainer, a first chamber on one side of the strainer, a second chamber on the other side of the strainer, an inlet, and a discharge for the first chamber, an outlet for eiiiuent and a pump discharge connection for the second chamber, said out-- let being above said discharge connection to maintain said chambers partially filled with eiliuent at all times, means for receiving the eilluent from said outlet, and a self priming centrifugal pump disposed above the level of said inlet for pumping liquid from said receiving means and discharging the same into the second chamber through said pump discharge connection to drive the eilluent and solid matter out through the discharge, said pump and its connections siphoninga part ot the eiiluent from said chambers to clean the pump, said Siphon being broken by air drawn into the outlet of said second chamber to form a trap in the pump to prevent the further flow of effluent through it.

2. In combination, a strainer, a lirst chamber on one side of the strainer, a second chamber on the otherside of the strainer, an

inlet and a discharge for the first chamber,

an outlet for eiiiuent and a lseparate pump discharge connection opening into the second chamber below the eiuent outlet, means .for receiving the effluent from said outlet,a pump for driving the effluent from said receiving means to said pump discharge connection, said pump having an inlet connection in the receiving means below said discharge connection and a valve in the strainer chamber to close said outlet for effluent, said valve being closed by pressure in said pump discharge connection when said pump 1s operated, and opened by siphoning as t e effluent in said second chamber fiushes back through the pump when it is shut down.

3. In combination, a sump, a' strainer box therein comprising a strainer, a first chamber on one side of the same, and a second chamber on the other side of the same, an inlet and a discharge for the first chamber, a check valve for said inlet, an outlet for efiluent for the second chamber, a pump having an inlet connection with the sump, a pump discharge connection for the second chamber, said sump receiving the efiiuent from said outlet, a valve for closing said outlet when the pump is operated, and an open bypass connection leading from said mlet to said sump. l

4. In combination, a pump, ,a strainer, a first chamber on one side of the same, a second chamber on the other side of the same, an inlet and a discharge for the first chamber, a check valve for said inlet, an outlet for effluent for the second chamber, a pump discharge connection for the second chamber, a sump for receivin the effluent from said outlet, a valve for c osing said outlet when the pump is operated, and an open by-pass connection leading from said inlet to said sump, said bypass comprising a stand-pipe, and a screen in said by-pass for intercepting solid matter. 1

5. In combination, a sump, a strainer box therein, a strainer dividing the b ox into a first compartment and a second compartment, an inlet connection for the first compartment, said connection comprising a check valve, a discharge connection communicating with the bottom of the first compartment, an outlet for eiiuent leading from the top of the second compartment to the sump to prevent effluent from flowing through it into the sump unless said second compartment is filled, a self priming centrifugal pump mounted above the sump, and having a suction connection leading into the sump and a discharge connection leading into the second compartment, said pump and its connections forming a Siphon which withdraws a part of the effluent from said second chamber to clean the pump and connections and subsequently forming a trap to check further outward flow of efiiuent through the pump.

6. In combination, a sump, a strainer box, a strainer dividing the box into a first compartment anda second compartment, an

inlet connection for the first compartment, said connection comprising a check valve, a discharge connection communicating with the bottom of the first compartment, an outlet for effluent leading from the second compartment to the sump, a self priming centrifugal pump mounted above the sump and havlng a suction connection leading into the sump and a discharge connection leading into the second compartment, and a valve actuated upon the operation of the pump for closing ofi' the said outlet, said pump and its connections forming a Siphon which withdraws a part of the effluent from said second chamber to clean the pump and connections and subsequently forming a trap to check further outward flow of effluent through the pump.

7. In combination, a sum a strainer box having a strainer dividing t 1e same into two compartments, a separate inlet for the first compartment, an overflow connection for said inlct leading into the sump, a check valve for the inlet between the overflow connection and the box, a discharge connection communicating with the lower part of the first compartment, said sump receiving the effluent from the second compartment, and a pump for forcing the effluent from said sump back through the strainer.

8. In combination, a sump, a Strainer box having a strainer dividing the same into two compartments,'a separate inlet for the first compartment, an overflow connection for said inlet leading into the sump, a check valve for the inlet between the overflow connection and the box, a discharge connection communicating with the lower part of the first compartment, said sump receiving the effluent from the ,second compartment, a pump for forcing the effluent from said sump back through the strainer, and a screen for intercepting solid matter at said overflow conection.

9. In combination, a sump, a strainer box having a strainer dividing the same into two compartments, a separate inlet for the first compartment, an overflow connection for said inlet, leading into said sump, a check valve for the inlet between the overflow connection and the box, a discharge connection communicating with the lower part of the first compartment, means for receiving the effluent from the second compartment, a pump for forcing the effluent from said receiving means back through the strainer, a screen for intercepting solid matter at said overflow connection, and hydraulic flushing means for simultaneously fiushing said strainer and said screen.

10. In combination, a sump, a strainer box having a strainer therein, a sewer inlet connection and a discharge connection communicating with the box on one side of the strainer, an outlet for effluent on the lll other side of the strainer, a self priming pump above the sewer inlet connection, t sald pump having an inlet leading 1nto the sump and a discharge connection leading into the strainer box on the sald other side of the strainer, said pump and its connections forming a si )hon which withdraws a part of the efiluent rom saidsecond chamber to clean theJ pump and connections and subsequently forming a trap to check further outward flow of eflluent through the pump.

11. In combination, a substantially cylindrical strainer box, a strainer thereln comrising a substantially fiat dia o nal plate ihr intercepting solid matter d1v1d1ng the box into a narrow bottomed chamber and a wide bottomed chamber, a discharge connection adjacent the lower end of the narrow bottom chamber, a sewa eV inlet connection for said strainer box on t e same side 0f the Screen as said discharge connection, a liquld inlet connection on the other side of the strainer a liquid outlet connection on the same si' e as said liquid inlet, and a valve 1n the strainer box for said li uid outlet having means adapted to receive t e impact of liquid from said liquid inlet connection.

12. In combination, a closed strainer box, a diagonal screen dividing the box into a first chamber and a second chamber, an inlet for raw sewage into the first compartment, a

check valve on the inside of said compartment for said inlet, a discharge connection lfor the first compartment communicating with the lower portion'of the same, a ump discharge connection connected to the ower part of the'second compartment, and an efiluent outlet for the second compartment, said outlet being provided with a valve in the strainer box adapted to be closed upon the inflow of liquid through the pump discharge connection.

13. In a system of the class described, a pit providing a sump, a strainer box in the pit above the sump, a screen defining two chambers in the strainer box, an inlet and a discharge connection for one chamber, a pump, the other chamber having. connection with the sump directly and through said,

pump, said direct connection being located above the pump connection to maintain the chamber filled, said pump connection comprising a portion extending above the inlet connection and forming a trap to prevent flow from the inlet through the pump while itis idle.

14. In a system of the class described,.a sump, a strainer box above the sump, a screen defining two chambers inthe strainer box, an inlet and a discharge connection for one chamber, a pump, the other chamber having a drain connection with the sump and having a connection with the sump through said pump, said pump connection comprising a portlon extending above the inlet connection to prevent back lfiow through the pump while it is idle, a valve for the drain connection, and control means for the valve operated bythe direction of flow through said pump connection for closing the valve when the pump is in operation and draw- A ing the valve open by siphonage upon stoppa e of the pum 15. n a system o the class described, a pit providing a sump, a'strainer box in the pit above `the sump, a screen defining two chambers in the strainer box, an inlet and a discharge connection for one chamber, a pump, the other chamber having a drain connection leading to the sump and having another connection leading to the ,sump

'through the pump, a valveyin/ the strainer box for the drainage connection, and a piston member connected to the valve and operated by the liquid passing through said pump connection.

16. In a system of the class described, the combination of a well the bottom thereof forminga sump, a separating box for separating out solids disposed in said well, said box having'an inlet and a discharge connec tion, said box having means for retaining solids adjacent said discharge connection, a drain connectionfor draining liquid from the box into the sump, a suction pump disposed a'bove the sump, and adapted to draw liquid from the sump and flush the solids out of the box through the discharge connection and adapted to clean itself by siphonage at the` completion of each of its operations.

17. In combination, a well, the bottom thereof forming a sump, a cover for the well,

a strainer box supported in the well above the sump, a strainer dividing the box into two parts, an incoming sewer pipe passing through the wall of the well and enterin one part of the box, a check valve in sai part controlling said pipe, an efliuent discharge pipe leading from the other part of the box, a sewage discharge pipe leading from the one part of the box, a self priming centrifugal pump mounted above the well and having an intake pipe leading down into the sump and a discharge pipe extending down into the well and connecting, with the other part of the box, and an automatic valve in the box for closing the eliluent discharge pipe when the pump is operated, said valve opening the effluent pipe responsive to back fiow through the pump immediately after the pump is shut down.

18. In combination a strainer, a first chamber on one side thereof, a second chamber on the other side thereof, an inlet and a discharge for the first chamber, an outlet for effluent, a pump discharge connection for charge connection, sald suction pipe, pump and ischarge pipe forming a siphon extendingabove the level of the intake and while the pump is idle actin as a trap to prevent the outward flow of e uent from the second chamber.

19. In combination a strainer, a first chamber on one side thereof, a second chamber on the other side thereof, an inlet and a discharge for the first chamber, an outlet for eluent andl a um discharge connection for the second c am er, the pump discharge being disposed in the lower part of the second chamber, means for receiving the efliuent from said outlet said meansy comprising a pit enclosing and extending below the strainer, and a self-priming centrifugal pump disposed above the level of the inlet, said pump `having a suction pipe extending down into `said pit and a discharge pipe extending to said pump discharge connection, said suction pipe, pump and discharge pipe forming an open connection providing an air trap extending above the level of the intake and preventing the outward flow of efHuent from the second chamber while the pump is idle.

20. The method of cleaning the pump and connections Iemployed to force eiiluent from a sump through an elevated screen box into a sewer which comprises, trapping a quantity of effluent inthe screen box, siphoning a part of that effluent through the pump and connections to clean them, breaking the siphon with air drawn into the screen box by 1t, and trapping that air in the pump to prevent further flow of eiiluent from the box through the pump.

21. In combination, a pit, the bottom of which forms a sump, a box in the upper part of said pit, means for maintaining said box partially full of liquid, a pump located above said pit, piping connecting the discharge side of said pump to said box below the level of the liquid in it and connecting the suction side of the pump to said sump, said pump being operated to suck liquid from said sump and to force it into said box, means for discharging the liquid from the box, and means including said pump and piping for siphoning a part of the liquid in said box through the pump in a reverse direction to clean it when it has been shut down.

22. In combination, a pit the bottom of which forms a sump, a strainer box located in the upper part of said pit, a screen separating said box into a solids compartment and an effluent compartment, an inlet located near the top of said solids compartment and an outlet below said inlet, an outlet for said effluent compartment located near its top through which eiiiuent flows into said sump after said box is filled above said solids compartment outlet, a pump located above said pit, a suction pipe extending 'from the pump to a point in the pit below said box, a discharge pipe extending from the pump to said eiiiuent compartment and entering it at a point below its outlet, said pump drawin elHuent from said sump and forcing it and the solids in said solids compartment out through said solids outlet, said pump and piping permitting effluent in said box to siphon back through the pump immediately after it has been shut down to flush out sediment sucked into the pump from said sump, and a valve in said box for closing said effluent outlet when said pump is in operation and for opening it responsive to said siphonage. 23. In combination, a. strainer box, a strainer therein separating the box into a first and a second chamber, said first chamber having an inlet located above its outlet, said second chamber having an outlet located below the inlet of the first chamber and above its outlet, an inlet for said second chamber located below its outlet and below the outlet of the first chamber, a pump located above said box, a sump located below the box. a pipe connection between the inlet of the second chamber and the discharge port of the pump, a suction pipe leading from said pump to said sump, means iol' admitting sewage to said first chamber in which chamber the solids are retained by said screen which permits the efiicient to pass into the second chamber and through its outlet into said sump, said sump being operated to withdraw the effluent from the sump and to torce it through the box to carry the solids in said first chamber through its outlet, a valve in the second chamber operated by pump pressure to close the outlet of said second chamber and operated by the siphoning of the eilluent in said second chamber through the pump when it is shut down to open said outlet, said outlet when open admitting air to the box to break said Siphon and thereby form a trap in said pump which prevents further flow of effluent through the pump to the sump.

In witness whereof, I hereunto subscribe my naine this 17th day of January, 1927.

HARRY E. LA BOUR.

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